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When Slide Rules Were Like Cellphones (hackaday.com)
szczys writes: Slide Rules and Pocket Protectors are the go-to items when making fun of old-time geeks. Forget the pocket protectors. Slide Rules were the first personal computers and a status symbol akin to what cellphones are today. Of course the general public wasn't attached to them, but engineers were. Before electronic calculators came around, everyone who needed to do some serious math owned Slide Rules. Stunningly easy to use and extremely effective, they have tick-marks placed on a logarithmic scale which makes complex multiplication, division, powers, etc. into visual calculations instead of mental ones.
The Jeppesen CR-3 Flight Computer is a circular slide rule that is still in use today. The circular slide rule has long been a tool of pilots, air traffic controllers and even bookmakers! It's not just science types that use slide rules.
There are many examples of fine old technology that can be admired for the ingenuity that went into devising non-digital solutions, and that depended on being precisely made.
Slide rules were nice. They were a working tool for just about a century, very roughly 1870 to 1970. There are always some virtues to old technology that are lost when it's supplanted by new--the discipline of keeping the characteristic in your head and never losing track of the order of magnitude, the freedom from the illusion of precision.
They were only mildly status symbols, at least at MIT during the 1960s. There was a certain amount of discussion of the comparative merits of Keuffel & Esser (wood) versus Pickett & Eckel (aluminum), whether it was better to fold the scales at pi or at the square root of ten, and so forth. Plenty of people got by with cheap slide rules. I never heard of any cases of slide rules being stolen.
Keeping them properly lubricated, keeping the scales aligned, keep everything tensioned just right so that the slide and the cursor would move easily when you slide them and then stay put when you stopped pushing was a bear. More than once, people were embarrassed when the slide would actually slip out of the slide rule and clatter on the floor.
When I saw my first HP-35 pocket calculator, $295 IIRC, I said "There, at least, is something that I'd accept in place of a slide rule--if you promised me it would last for decades and never break.
Yes, I feel some nostalgia for slide rules--but let's not exaggerate.
Oh, by the way--that "2 x 2 is 3.96" joke above is wrong. On an exact answer like that, on a well-made slide rule if you put the index of the C scale over 2 on the D scale--and you can get it so that it looks perfect, and the eye has darn good vernier acuity--the 2 on the C scale will be perfectly aligned with the 4 on the D scale. You would read it as "4." You couldn't possibly read it as 3.96, 3.96 is two full scale divisions away from 4.
The problem comes when the answer lies between two scale divisions. For example, 3.98 and 4.00 are two adjacent marks. You would be hard-pressed to tell whether an answer were, say, 3.99 or 3.993.
"How to Do Nothing," kids activities, back in print!
I know it's a joke, but I actually read the article and used the online web simulator to work though the example problem that the article suggested. It was a very simple problem... What is 2 times 3. Obviously, any grade schooler can tell you the answer is 6, but using the slide rule as accurately as possible, I came up with 5.5. If that's an example of the accuracy of a slide rule, then good riddance!
I wouldn't say that's an example of the accuracy of a slide rule. Rather, I'd say it's an example of your lack of skill with one.
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